Flexible metallic conduit.



No. 640,758. Patented lan. 9, i900. E. T. GREENFIELD.

FLEXIBLE METALLIC CONDUlT.

(Application filed July 17, 1899.)

(No Model.)

wbb/lego @o YH: mams mins oo, PHnroLlrwo.. wAsmNo TTTTTT c,

UNITED STATES PATENT OFFICE,

EDVIN T. GREENFIELD, OF NEIV YORK, Il. Y.

FLEXIBLE METALLIC CONDUIT.

SPECIFICATION forming part of Letters Patent No. 640,758, dated January9, 19OG.

Application filed July 17, 1899. Serial No. 724,060. (No model.)

To cti/Z whom t may concern/.-

Be it known that I, EDWIN T. GREENETELD, a citizen of the United States,residing at New York, in the borough of Manhattan, county of New York,and State of New York, have made a new and useful Improvement inFlexible Metallic Conduits, of which the following is a specification.

My improvement has for its object to provide means for giving to theends of flexible and other lmetallic conduits, like those disclosed in aprior patent granted to me on the 8th day of August, 1899, and numbered630,591, smoothed or finished ends.

In the before-mentioned patent I have described and shown a flexiblemetallic tube composed of two interlocking strips of metal spirally wound the one about the other. In using such conduits it is found thatwhere the ends are sawed off there is always left a jagged surface,which endangers the insulation of wires being drawn into the innersurface thereof, and it was with a View of overcoming this objectionablefeature that the present improvement was devised.

My improvement will be understood by referring to the accompanyingdrawings, in which- Figure l illustrates in side elevational view ashort section of liexible metallic conduit like that disclosed in thebefore-mentioned patent and also like that disclosed in prior patentsgranted to me, the same being composed of interlocking strips of metal.Said figure also illustrates the improved bushingring for overcoming theevil effects of the jagged ends of said conduit and the tool for puttingthe same in place. Fig. 2 is a longitudinal sectional view taken throughthe body of Fig. l, illustrating the manner of using the tool, thebushing-ring being in place within the end of the conduit. Fig. 3 is atransverse sectional view taken through Fig. l on the line 00 a; and asseen looking thereat in the direction of the arrows from the righttoward the left hand end of the drawings. Fig. 4 is a longitudinalsectional View illustrating the completion of the use of the tool ininserting the bushing-ring within the end of the conduit, the tool beingshown partly in sectional and partly in side elevational viewe Referringnow to the drawings and first to Fig. l, A and B represent theinterlocking metallic strips which constitute or compose when woundtogether my novel form of conduit. It is foundin actual use of thebeforementioned conduit that when the same is sawed off there alwaysresult ragged edges or jagged ends t f, which by reason of their sharpedges necessarily endanger the insulation of wires being drawn into theinner surface of the conduit. My present improvenient is designed toovercome this objectionable feature, and to this end I form anexpansible metallic bushing-ring C, preferably of lead and having aiiange I, adapted to overlap or conceal the endstt and the ragged sawededges when put into position in the inner end of the conduit. For thepurpose of putting this ring in position I have devised a toolconsisting of a body part D, having a handle II, said body part beingcone-shaped at E for a definite part of its length and adapted to beinserted through an expander, consisting of four expansible parts F F2F3 Ff, constructed by slitting a tube with parallel slits K to a pointnear one end thereof, the other end thereof having shoulders L,adaptedto come into mechanical bearing with the corresponding body part D whenthrust firmly home.

.I is a detachable head for holding the parts together.

The result sought by my novel means and with the novel tool hereinbeforedescribed I effect as follows: The expansible bushingring C is put intoposition in the end of the conduit and the tool is inserted with theexpander at its extreme left-hand position. It is then forced inward byhitting the outer end of the body part D successive blows with a hammer.Thus the cone-shaped part E causes the expander F F2 FS F4 to expand thecylindrical body part of the bushing-ring outward against the innersurface of the flexible metallic conduit, thereby causing the saine tobe firmly secured. Finally when the shoulder L comes into mechanicalcontact with the flange I of the bushing-ring and the shoulder of thebody part D into like mechanical contact with the shoulder L theoperator takes hold of the handle I-I and rotates the entire tool untilthe bushing-ring is firmly and se- IOO curely locked in position in andagainst the end 'of the conduit, thus making a completed smooth endwhich Will not offer any obstruction to insulated Wires when being putin place.

l do not limit my improvement to the especial means herein shown anddescribed for effecting the result sought, as I believe l am broadlyentitled to claim means in the nature of an expansible bushing-ring forprotecting or covering the jagged edges at the end of a flexiblemetallic conduit and when combined therewith; nor do limit myself to theuse of the improved means for protecting or covering the jagged ends ofa metallic conduit in connection with a flexible conduit, as it isobvious that the same means might be used in connection with ordinaryiron or steel tubular conduits, and my claims are designed to be of suchscope as to include all such uses.

l make no claim in the present application to the tool herein shown anddescribed for placing a protecting-bushing in the end of a v metallicconduit, as the same constitutes the subject-matter of a separate ordivisional application bearing Serial No. 728,956, filed by me in theUnited States Patent Office on the th day of August, 1899.

Having thus described my invention, what I claim, and desire to secureby Letters Patent of the United States, is-

l. A metallic conduit having jagged ends, in combination With abushing-ring secured to the inner surface and end thereof, substantiallyas described.

2. A metallic conduit having jagged ends, in combination with abushing-ring secured to the inner surface thereof, said ring beingprovided with a flange Which covers the end of the conduit,substantially as described.

3. Ametallic conduit provided with a bushing-ring, said ring beingsecured against the inner surface of the conduit and provided with aflange which rests against the end thereof, substantially as described.

4. A flexible conduit composed of interlocking metallic strips providedWith bushing-rings at its opposite ends, said rings being securedagainst the inner surface of the conduit and having flanges which restagainst the ends thereof, substantially as described.

In testimony whereof l have hereunto subscribed my name this 5th day ofJuly, 1399.

EDWIN GREENFIELD.

Witnesses:

C. J. KINTNER, M. F. HEATING.

